$spacer: 1rem !default;
$spacers: () !default;
$spacers: map-merge(
    (
      0: 0,
      1: ($spacer * .25),
      2: ($spacer * .5),
      3: $spacer,
      4: ($spacer * 1.5),
      5: ($spacer * 2.5),
      10: ($spacer * 3),
      16: ($spacer * 4),
      20: ($spacer * 5)
    ),
    $spacers
);
